*(for an 02 Raptor)*i have been periodically checking my plug since doing my mods. well it looked fine for the first while, now after 25-30 hrs of riding i checked my plug again and its BLACK. Everything is just coated with black residue looking.Thick. I am running the full Sparks x6 exhaust, pro flow w K&N, air box lid ON w 2-2" holes drilled in back of lid, snorkle flaps trimmed out, roughly 1200 above sea level...Jetting: gytr jet kit, needles ,25 pilot, 160/165, air/fuel screws: both at 3 turns out ***i started at 2 1/2 and 2 3/4 but i slowly worked my way up to what im running now before it would stop backfiring on deceleration

** ************Ok, i went ahead and removed my air box lid, well it runs like ****, WAY WAY more power with my lid on, not too sure what to do now, like it is a night and day difference with it on and off...with it "on" it runs STRONG all the way from bottom to top..Im gonna do another plug check and see..thanks for all the help********************

 

move the clips up 1 or decrease jet sizes to 155/150

need more info really but you make it sound too rich and I kinda think it probably is

with a lid on, 148/150 is probably good

 

TTT!!!

 

remove your lid and tha will fix it....

 

What type of filter do i need for the crankcase breather??

 

If it used to be OK, but now is black, check your valve clearance. Stock raptor valves are soft and the seat wears out quickly. This causes the valve lash to tighten. The valves end up not seating if the valve lash isn't kept in spec. This lowers the aiflow thru the engine and makes it run rich.

Been there done that!

 

I actually jus did my valves before i put the new plug in, but i will check again for clearances

 

My guess is you're running a little rich, just try different combos ( I know the jetting on a Raptor is a pain in the *** )

 

TTT!